Dynamically managing a table of contents

ABSTRACT

A computer-implemented method according to one embodiment includes receiving a request to initialize a storage device, identifying a size of the storage device to be initialized, determining a size of a table of contents and a location for the table of contents within the storage device, based on the identified size of the storage device to be initialized, determining a type of the table of contents; and initializing the storage device, utilizing the determined size of the table of contents, the determined location for the table of contents, and the determined type of the table of contents.

BACKGROUND

The present invention relates to data management, and more specifically,this invention relates to managing a table of contents within a storagevolume.

A table of contents is an important component of a storage volume.However, current methods for creating and maintaining a table ofcontents within a storage volume exhibit various limitations. Forexample, currently, a table of contents is limited to a single extent ofcontiguous tracks. This restriction may be enforced even when increasingthe size of an existing table of contents. Additionally, users creatingand managing storage volumes currently have to manually create andmanage many aspects of the table of contents within the storage volumes.

SUMMARY

A computer-implemented method according to one embodiment includesreceiving a request to initialize a storage device, identifying a sizeof the storage device to be initialized, determining a size of a tableof contents and a location for the table of contents within the storagedevice, based on the identified size of the storage device to beinitialized, determining a type of the table of contents; andinitializing the storage device, utilizing the determined size of thetable of contents, the determined location for the table of contents,and the determined type of the table of contents.

According to another embodiment, a computer program product fordynamically managing a table of contents comprises a computer readablestorage medium having program instructions embodied therewith, where thecomputer readable storage medium is not a transitory signal per se, andwhere the program instructions are executable by a processor to causethe processor to perform a method. The method comprises receiving, bythe processor, a request to initialize a storage device, identifying, bythe processor, a size of the storage device to be initialized,determining, by the processor, a size of the table of contents and alocation for the table of contents within the storage device, based onthe identified size of the storage device to be initialized,determining, by the processor, a type of the table of contents, andinitializing, by the processor, the storage device, utilizing thedetermined size of the table of contents, the determined location forthe table of contents, and the determined type of the table of contents.

A system according to another embodiment includes a processor and logicintegrated with and/or executable by the processor, where the logic isconfigured to receive a request to initialize a storage device, identifya size of the storage device to be initialized, determine a size of atable of contents and a location for the table of contents within thestorage device, based on the identified size of the storage device to beinitialized, determine a type of the table of contents, and initializethe storage device, utilizing the determined size of the table ofcontents, the determined location for the table of contents, and thedetermined type of the table of contents.

Other aspects and embodiments of the present invention will becomeapparent from the following detailed description, which, when taken inconjunction with the drawings, illustrate by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a network architecture, in accordance with oneembodiment.

FIG. 2 shows a representative hardware environment that may beassociated with the servers and/or clients of FIG. 1, in accordance withone embodiment.

FIG. 3 illustrates a tiered data storage system in accordance with oneembodiment.

FIG. 4 illustrates a method for dynamically managing a table ofcontents, in accordance with one embodiment.

FIG. 5 illustrates a method for initializing a volume table of contents(VTOC) for a new storage volume, in accordance with one embodiment.

FIG. 6 illustrates a method for expanding a volume table of contents(VTOC), in accordance with one embodiment.

DETAILED DESCRIPTION

The following description discloses several preferred embodiments ofsystems, methods and computer program products for dynamically managinga table of contents. Various embodiments provide a method to notifyhardware storage of unallocated data that can then be read inhibited.

The following description is made for the purpose of illustrating thegeneral principles of the present invention and is not meant to limitthe inventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.

Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless otherwise specified. It will be further understood thatthe terms “includes” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

The following description discloses several preferred embodiments ofsystems, methods and computer program products for dynamically managinga table of contents.

In one general embodiment, a computer-implemented method includesreceiving a request to initialize a storage device, identifying a sizeof the storage device to be initialized, determining a size of a tableof contents and a location for the table of contents within the storagedevice, based on the identified size of the storage device to beinitialized, determining a type of the table of contents; andinitializing the storage device, utilizing the determined size of thetable of contents, the determined location for the table of contents,and the determined type of the table of contents

In another general embodiment, a computer program product fordynamically managing a table of contents comprises a computer readablestorage medium having program instructions embodied therewith, where thecomputer readable storage medium is not a transitory signal per se, andwhere the program instructions are executable by a processor to causethe processor to perform a method. The method comprises receiving, bythe processor, a request to initialize a storage device, identifying, bythe processor, a size of the storage device to be initialized,determining, by the processor, a size of the table of contents and alocation for the table of contents within the storage device, based onthe identified size of the storage device to be initialized,determining, by the processor, a type of the table of contents, andinitializing, by the processor, the storage device, utilizing thedetermined size of the table of contents, the determined location forthe table of contents, and the determined type of the table of contents.

In another general embodiment, a system includes a processor and logicintegrated with and/or executable by the processor, where the logic isconfigured to receive a request to initialize a storage device, identifya size of the storage device to be initialized, determine a size of atable of contents and a location for the table of contents within thestorage device, based on the identified size of the storage device to beinitialized, determine a type of the table of contents, and initializethe storage device, utilizing the determined size of the table ofcontents, the determined location for the table of contents, and thedetermined type of the table of contents.

FIG. 1 illustrates an architecture 100, in accordance with oneembodiment. As shown in FIG. 1, a plurality of remote networks 102 areprovided including a first remote network 104 and a second remotenetwork 106. A gateway 101 may be coupled between the remote networks102 and a proximate network 108. In the context of the presentarchitecture 100, the networks 104, 106 may each take any formincluding, but not limited to a LAN, a WAN such as the Internet, publicswitched telephone network (PSTN), internal telephone network, etc.

In use, the gateway 101 serves as an entrance point from the remotenetworks 102 to the proximate network 108. As such, the gateway 101 mayfunction as a router, which is capable of directing a given packet ofdata that arrives at the gateway 101, and a switch, which furnishes theactual path in and out of the gateway 101 for a given packet.

Further included is at least one data server 114 coupled to theproximate network 108, and which is accessible from the remote networks102 via the gateway 101. It should be noted that the data server(s) 114may include any type of computing device/groupware. Coupled to each dataserver 114 is a plurality of user devices 116. User devices 116 may alsobe connected directly through one of the networks 104, 106, 108. Suchuser devices 116 may include a desktop computer, lap-top computer,hand-held computer, printer or any other type of logic. It should benoted that a user device 111 may also be directly coupled to any of thenetworks, in one embodiment.

A peripheral 120 or series of peripherals 120, e.g., facsimile machines,printers, networked and/or local storage units or systems, etc., may becoupled to one or more of the networks 104, 106, 108. It should be notedthat databases and/or additional components may be utilized with, orintegrated into, any type of network element coupled to the networks104, 106, 108. In the context of the present description, a networkelement may refer to any component of a network.

According to some approaches, methods and systems described herein maybe implemented with and/or on virtual systems and/or systems whichemulate one or more other systems, such as a UNIX system which emulatesan IBM z/OS environment, a UNIX system which virtually hosts a MICROSOFTWINDOWS environment, a MICROSOFT WINDOWS system which emulates an IBMz/OS environment, etc. This virtualization and/or emulation may beenhanced through the use of VMWARE software, in some embodiments.

In more approaches, one or more networks 104, 106, 108, may represent acluster of systems commonly referred to as a “cloud.” In cloudcomputing, shared resources, such as processing power, peripherals,software, data, servers, etc., are provided to any system in the cloudin an on-demand relationship, thereby allowing access and distributionof services across many computing systems. Cloud computing typicallyinvolves an Internet connection between the systems operating in thecloud, but other techniques of connecting the systems may also be used.

FIG. 2 shows a representative hardware environment associated with auser device 116 and/or server 114 of FIG. 1, in accordance with oneembodiment. Such figure illustrates a typical hardware configuration ofa workstation having a central processing unit 210, such as amicroprocessor, and a number of other units interconnected via a systembus 212.

The workstation shown in FIG. 2 includes a Random Access Memory (RAM)214, Read Only Memory (ROM) 216, an I/O adapter 218 for connectingperipheral devices such as disk storage units 220 to the bus 212, a userinterface adapter 222 for connecting a keyboard 224, a mouse 226, aspeaker 228, a microphone 232, and/or other user interface devices suchas a touch screen and a digital camera (not shown) to the bus 212,communication adapter 234 for connecting the workstation to acommunication network 235 (e.g., a data processing network) and adisplay adapter 236 for connecting the bus 212 to a display device 238.

The workstation may have resident thereon an operating system such asthe Microsoft Windows® Operating System (OS), a MAC OS, a UNIX OS, etc.It will be appreciated that a preferred embodiment may also beimplemented on platforms and operating systems other than thosementioned. A preferred embodiment may be written using XML, C, and/orC++ language, or other programming languages, along with an objectoriented programming methodology. Object oriented programming (OOP),which has become increasingly used to develop complex applications, maybe used.

Now referring to FIG. 3, a storage system 300 is shown according to oneembodiment. Note that some of the elements shown in FIG. 3 may beimplemented as hardware and/or software, according to variousembodiments. The storage system 300 may include a storage system manager312 for communicating with a plurality of media on at least one higherstorage tier 302 and at least one lower storage tier 306. The higherstorage tier(s) 302 preferably may include one or more random accessand/or direct access media 304, such as hard disks in hard disk drives(HDDs), nonvolatile memory (NVM), solid state memory in solid statedrives (SSDs), flash memory, SSD arrays, flash memory arrays, etc.,and/or others noted herein or known in the art. The lower storagetier(s) 306 may preferably include one or more lower performing storagemedia 308, including sequential access media such as magnetic tape intape drives and/or optical media, slower accessing HDDs, sloweraccessing SSDs, etc., and/or others noted herein or known in the art.One or more additional storage tiers 316 may include any combination ofstorage memory media as desired by a designer of the system 300. Also,any of the higher storage tiers 302 and/or the lower storage tiers 306may include some combination of storage devices and/or storage media.

The storage system manager 312 may communicate with the storage media304, 308 on the higher storage tier(s) 302 and lower storage tier(s) 306through a network 310, such as a storage area network (SAN), as shown inFIG. 3, or some other suitable network type. The storage system manager312 may also communicate with one or more host systems (not shown)through a host interface 314, which may or may not be a part of thestorage system manager 312. The storage system manager 312 and/or anyother component of the storage system 300 may be implemented in hardwareand/or software, and may make use of a processor (not shown) forexecuting commands of a type known in the art, such as a centralprocessing unit (CPU), a field programmable gate array (FPGA), anapplication specific integrated circuit (ASIC), etc. Of course, anyarrangement of a storage system may be used, as will be apparent tothose of skill in the art upon reading the present description.

In more embodiments, the storage system 300 may include any number ofdata storage tiers, and may include the same or different storage memorymedia within each storage tier. For example, each data storage tier mayinclude the same type of storage memory media, such as HDDs, SSDs,sequential access media (tape in tape drives, optical disk in opticaldisk drives, etc.), direct access media (CD-ROM, DVD-ROM, etc.), or anycombination of media storage types. In one such configuration, a higherstorage tier 302, may include a majority of SSD storage media forstoring data in a higher performing storage environment, and remainingstorage tiers, including lower storage tier 306 and additional storagetiers 316 may include any combination of SSDs, HDDs, tape drives, etc.,for storing data in a lower performing storage environment. In this way,more frequently accessed data, data having a higher priority, dataneeding to be accessed more quickly, etc., may be stored to the higherstorage tier 302, while data not having one of these attributes may bestored to the additional storage tiers 316, including lower storage tier306. Of course, one of skill in the art, upon reading the presentdescriptions, may devise many other combinations of storage media typesto implement into different storage schemes, according to theembodiments presented herein.

According to some embodiments, the storage system (such as 300) mayinclude logic configured to receive a request to open a data set, logicconfigured to determine if the requested data set is stored to a lowerstorage tier 306 of a tiered data storage system 300 in multipleassociated portions, logic configured to move each associated portion ofthe requested data set to a higher storage tier 302 of the tiered datastorage system 300, and logic configured to assemble the requested dataset on the higher storage tier 302 of the tiered data storage system 300from the associated portions.

Of course, this logic may be implemented as a method on any deviceand/or system or as a computer program product, according to variousembodiments.

Now referring to FIG. 4, a flowchart of a method 400 is shown accordingto one embodiment. The method 400 may be performed in accordance withthe present invention in any of the environments depicted in FIGS. 1-3and 5, among others, in various embodiments. Of course, more or lessoperations than those specifically described in FIG. 4 may be includedin method 400, as would be understood by one of skill in the art uponreading the present descriptions.

Each of the steps of the method 400 may be performed by any suitablecomponent of the operating environment. For example, in variousembodiments, the method 400 may be partially or entirely performed byone or more servers, computers, or some other device having one or moreprocessors therein. The processor, e.g., processing circuit(s), chip(s),and/or module(s) implemented in hardware and/or software, and preferablyhaving at least one hardware component may be utilized in any device toperform one or more steps of the method 400. Illustrative processorsinclude, but are not limited to, a central processing unit (CPU), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), etc., combinations thereof, or any other suitablecomputing device known in the art.

As shown in FIG. 4, method 400 may initiate with operation 402, where arequest is received to initialize a storage device. In one embodiment,the storage device may include a storage volume for storing data. Forexample, the storage device may include a direct access storage device(DASD) used to store data for one or more users. In another embodiment,the storage device may include physical storage space. For example, thestorage device may include an extent-based file system that includes aplurality of physical tracks. In another embodiment, the storage devicemay include one or more hard disk drives, one or more memory units, oneor more caches, etc. In yet another embodiment, the storage device mayinclude a storage volume.

Additionally, in one embodiment, the request to initialize the storagedevice may be received from one or more users. For example, a system mayreceive a user request to add storage to an account associated with theuser. In another embodiment, additional data may be received inassociation with the request. For example, a serial number (e.g., avolume serial number, etc.) associated with the storage device may bereceived within or in conjunction with the request to initialize thestorage device.

Further, as shown in FIG. 4, method 400 may proceed with operation 404,where a size of the storage device to be initialized is identified. Inone embodiment, the size of the storage device may include an amount ofdata (e.g., a number of bytes, etc.) able to be stored within thestorage device. In another embodiment, the size of the storage devicemay be indicated within the request to initialize the storage device. Inyet another embodiment, the size of the storage device may be determinedfrom one or more default storage sizes.

Further still, as shown in FIG. 4, method 400 may proceed with operation406, where a size of a table of contents and a location for the table ofcontents within the storage device are determined, based on theidentified size of the storage device to be initialized. In oneembodiment, the table of contents may include a data structure thatenables the identification and location of data stored within thestorage device. In another embodiment, the table of contents may storeone or more instances of metadata. For example, the table of contentsmay store a size of stored data, a location of stored data, permissionsassociated with stored data, etc. In yet another embodiment, the tableof contents may include a volume table of contents (VTOC) within a z/OSoperating system. In another embodiment, the size of the table ofcontents may include a predetermined amount of data (e.g., apredetermined number of tracks, etc.) within the storage device that isreserved for use by the table of contents.

Additionally, in one embodiment, the table of contents may include oneor more pointers. For example, user data within the storage device maybe kept in one or more data sets, and pointers to these data sets may bemaintained within one or more data set control block (DSCB) records inthe table of contents. In another embodiment, the storage device mayinclude an index data set that has pointers to data set DSCB records inthe table of contents.

Also, in one embodiment, the size of the table of contents and thelocation for the table of contents within the storage device may bedetermined utilizing one or more algorithms. In another embodiment, thesize of the table of contents may be determined as a predeterminedpercentage of the identified size of the storage device to be initiated.In yet another embodiment, the table of contents may be determined to belocated at the beginning of the storage device, at the end of thestorage device, or within a predetermined location of the storage devicebased on an analysis of the size of the storage device. In still anotherembodiment, the location for the table of contents within the storagedevice may include a place where the table of contents is stored withinthe storage device.

Furthermore, as shown in FIG. 4, method 400 may proceed with operation408, where a type of the table of contents is determined. In oneembodiment, the type of the table of contents may be determined based onone or more criteria. For example, the type of the table of contents maybe determined based on an analysis of the size of the storage device tobe initialized. In another example, the type of the table of contentsmay be determined based on one or more defaults. For example, the typeof the table of contents may be a default type that is automaticallyselected.

In another embodiment, the type of the table of contents may include astate of the table of contents, a way in which data is stored within thetable of contents, etc. For example, the type of the table of contentsmay include an operating system VTOC (OSVTOC) type where free spacewithin the table of contents is mapped by free space records (e.g., dataset control block (DSCB) records, etc.) within the VTOC. In anotherexample, the type of the table of contents may include an indexed VTOCtype where the VTOC index data set manages an allocation of space withinthe storage device.

Further still, as shown in FIG. 4, method 400 may proceed with operation410, where the storage device is initialized, utilizing the determinedsize of the table of contents, the determined location for the table ofcontents, and the determined type of the table of contents. In oneembodiment, initializing the storage device may include adding thestorage device to a system. For example, the storage device may bephysically or logically added to a system, where the system may be oneof a plurality of systems within an environment (e.g., a sysplex, etc.).In another embodiment, initializing the storage device may includecreating the table of contents, reserving a physical area of the storagedevice for the table of contents using a physical extent, and insertingthe table of contents into the storage device, where the table ofcontents has the determined size of the table of contents, thedetermined location for the table of contents within the storage device,and the determined type of the table of contents.

Further still, in one embodiment, the initializing of the storage devicemay be performed automatically. For example, the initializing of thestorage device may be performed by a system without the need forintervention or input by one or more users requesting to initialize thestorage device. In this way, the creation and management of the table ofcontents within the storage device may be performed automaticallywithout the need for manual intervention by one or more users.

Also, in one embodiment, it may be determined that an amount of dataused by the table of contents within the storage device has reached apredetermined size. For example, it may be determined by the system thatthe table of contents is full or has a size that exceeds a threshold. Inanother example, it may be determined that the table of contents hasused a predetermined amount of data (e.g., to store metadata, pointers,etc.) within the storage device that is reserved for use by the table ofcontents.

Additionally, in one embodiment, in response to the determination thatthe amount of data used by the table of contents within the storagedevice has reached the predetermined size, an additional portion of thetable of contents that may or may not be contiguous to the table ofcontents may be created within the storage device. For example, anadditional predetermined amount of data (e.g., a predetermined number oftracks, etc.) within the storage device may be reserved for use by thetable of contents using an additional physical extent, where theadditional predetermined amount of data may or may not be contiguouswith/adjacent to the predetermined amount of data originally reservedfor use by the table of contents.

In another embodiment, the additional portion of the table of contentsmay be linked to the table of contents within the storage device. Forexample, the original table of contents may be associated with a firstphysical extent within the storage device, the additional portion of thetable of contents may be associated with a second physical extent withinthe storage device, and the first and second physical extents may belinked (e.g., via one or more pointers, etc.).

Furthermore, in one embodiment, the storage device may be analyzed, andthe type of the table of contents may be changed, based on the analysis.For example, the type of the table of contents may include an OSVTOCtype, and an analysis of a number of data sets within the storage deviceand a size of the storage device may indicate that changing the type ofthe table of contents to an indexed VTOC type may increase theperformance of the storage device. In another example, the type of thetable of contents may be switched from the OSVTOC type to the indexedVTOC type, in response to the analysis. In this way, a type of the tableof contents may be dynamically adjusted for optimal performance of thestorage device.

Further still, in one embodiment, an error associated with the table ofcontents may be identified and automatically resolved. For example, thetype of the table of contents may include an indexed VTOC type, and thesystem may monitor the table of contents and may detect an errorassociated with the table of contents. In another example, in responseto the error detection, the error may be resolved automatically by thesystem, which still maintaining the table of contents as an indexed VTOCtype (e.g., without having to revert the table of contents to an OSVTOCtype, etc.).

Now referring to FIG. 5, a flowchart of a method 500 for initializing avolume table of contents (VTOC) for a new storage volume is shownaccording to one embodiment. The method 500 may be performed inaccordance with the present invention in any of the environmentsdepicted in FIGS. 1-4 and 6, among others, in various embodiments. Ofcourse, more or less operations than those specifically described inFIG. 5 may be included in method 500, as would be understood by one ofskill in the art upon reading the present descriptions.

Each of the steps of the method 500 may be performed by any suitablecomponent of the operating environment. For example, in variousembodiments, the method 500 may be partially or entirely performed byone or more servers, computers, or some other device having one or moreprocessors therein. The processor, e.g., processing circuit(s), chip(s),and/or module(s) implemented in hardware and/or software, and preferablyhaving at least one hardware component may be utilized in any device toperform one or more steps of the method 500. Illustrative processorsinclude, but are not limited to, a central processing unit (CPU), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), etc., combinations thereof, or any other suitablecomputing device known in the art.

As shown in FIG. 5, method 500 may initiate with operation 502, where arequest is received to initialize a direct access storage device (DASD)volume within a z/OS environment. In one embodiment, the request may bereceived from a storage administrator associated with an account withinthe z/OS environment. For example, the storage administrator may requestthat additional storage be added to their associated account within asysplex. In another embodiment, the request may include a volume serialnumber.

Additionally, method 500 may proceed with operation 504, where a sizeand location of a volume table of contents (VTOC) for the DASD aredetermined based on a size of the DASD volume. In one embodiment, theVTOC location and size may be determined using an algorithm that takesinto consideration the size of the DASD volume.

Further, method 500 may proceed with operation 506, where it isdetermined whether the VTOC for the DASD has an operating system VTOC(OSVTOC) state or an indexed VTOC state. In one embodiment, a number ofdata sets on the DASD volume may be analyzed to determine whether theOSVTOC state or the indexed VTOC state provides the DASD volume withhigher performance. In another embodiment, when the DASD volume is firstinitialized, it may be set as an OSVTOC until one or more datasets areallocated.

Further still, method 500 may proceed with operation 508, where the VTOChaving the determined size and state is inserted into the DASD at thedetermined location. In one embodiment, DASD technology may use an arraywhere data is distributed across disks, such that the physical locationof the data is virtualized. In this way, a VTOC may be placed by thesystem in one or more of a variety of locations within the DASD volume.In another embodiment, if an indexed VTOC state is implemented, a sizeof the index may be determined based off the size of the VTOC. Furtherstill, in one embodiment, the system may monitor the VTOC so that if anerror is detected that would have normally disabled an indexed VTOC, theerror may be fixed and the VTOC will remain indexed.

Now referring to FIG. 6, a flowchart of a method 600 for expanding avolume table of contents (VTOC) is shown according to one embodiment.The method 600 may be performed in accordance with the present inventionin any of the environments depicted in FIGS. 1-5, among others, invarious embodiments. Of course, more or less operations than thosespecifically described in FIG. 6 may be included in method 600, as wouldbe understood by one of skill in the art upon reading the presentdescriptions.

Each of the steps of the method 600 may be performed by any suitablecomponent of the operating environment. For example, in variousembodiments, the method 600 may be partially or entirely performed byone or more servers, computers, or some other device having one or moreprocessors therein. The processor, e.g., processing circuit(s), chip(s),and/or module(s) implemented in hardware and/or software, and preferablyhaving at least one hardware component may be utilized in any device toperform one or more steps of the method 600. Illustrative processorsinclude, but are not limited to, a central processing unit (CPU), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), etc., combinations thereof, or any other suitablecomputing device known in the art.

As shown in FIG. 6, method 600 may initiate with operation 602, where itis determined that a first data set extent for a volume table ofcontents (VTOC) has become full within a storage volume. In oneembodiment, it may be determined that the VTOC has become full when alldata allocated for the VTOC within a storage volume has been used by theVTOC. In another embodiment, the data allocated for the VTOC within astorage volume may be indicated by the data set extent. In yet anotherembodiment, the VTOC may include a record (e.g., the first record of theVTOC, etc.) which describes the device the volume resides on, the volumeattributes, and the size and contents of the VTOC data set. In anotherexample, the record in the VTOC may include a VTOC DSCB (format-4).

Additionally, method 600 may initiate with operation 604, where a secondVTOC data set extent for the VTOC is created in an area that may or maynot be contiguous with the first data set extent for the VTOC within thestorage volume, in response to the determination. In one embodiment, thesecond VTOC data set extent may reserve an additional storage area(e.g., one or more tracks, etc.) within the storage volume.

Further, method 600 may initiate with operation 606, where the secondVTOC data set extent is connected to the first VTOC data set extentwithin the storage volume. For example, a record located in the firstVTOC data set extent (e.g., the VTOC DSCB (format-4), etc.) may beupdated to point to the second VTOC data set extent. In anotherembodiment, additional space may be added to the storage volumedynamically.

In this way, creation of VTOC extents may be chained to the originalVTOC by having the first VTOC extent point to the second VTOC extent,the second VTOC extent point to the third VTOC extent, and so on untilthe last VTOC extent is reached. By allowing the VTOC to be in multipleextents, the VTOC may grow if needed as data sets are allocated. Thismay eliminate a need for a storage administrator to have to manuallyexpand the VTOC. In another embodiment, a unit control block (UCB) maypoint to the first data set extent for the VTOC.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein includes anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which includes one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Moreover, a system according to various embodiments may include aprocessor and logic integrated with and/or executable by the processor,the logic being configured to perform one or more of the process stepsrecited herein. By integrated with, what is meant is that the processorhas logic embedded therewith as hardware logic, such as an applicationspecific integrated circuit (ASIC), a FPGA, etc. By executable by theprocessor, what is meant is that the logic is hardware logic; softwarelogic such as firmware, part of an operating system, part of anapplication program; etc., or some combination of hardware and softwarelogic that is accessible by the processor and configured to cause theprocessor to perform some functionality upon execution by the processor.Software logic may be stored on local and/or remote memory of any memorytype, as known in the art. Any processor known in the art may be used,such as a software processor module and/or a hardware processor such asan ASIC, a FPGA, a central processing unit (CPU), an integrated circuit(IC), a graphics processing unit (GPU), etc.

It will be clear that the various features of the foregoing systemsand/or methodologies may be combined in any way, creating a plurality ofcombinations from the descriptions presented above.

It will be further appreciated that embodiments of the present inventionmay be provided in the form of a service deployed on behalf of acustomer to offer service on demand.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of a preferred embodiment shouldnot be limited by any of the above-described exemplary embodiments, butshould be defined only in accordance with the following claims and theirequivalents.

What is claimed is:
 1. A computer-implemented method, comprising:receiving a request to initialize a storage device; identifying a sizeof the storage device to be initialized; determining a size of a tableof contents and a location for the table of contents within the storagedevice, based on the identified size of the storage device to beinitialized; determining a type of the table of contents; andinitializing the storage device, utilizing the determined size of thetable of contents, the determined location for the table of contents,and the determined type of the table of contents.
 2. Thecomputer-implemented method of claim 1, wherein a volume serial numberassociated with the storage device is received with the request toinitialize the storage device.
 3. The computer-implemented method ofclaim 1, wherein the table of contents stores a size of stored data, alocation of the stored data, permissions associated with the storeddata.
 4. The computer-implemented method of claim 1, wherein the type ofthe table of contents includes an operating system volume table ofcontents (OSVTOC) type where free space within the table of contents ismapped by data set control block (DSCB) records within the table ofcontents.
 5. The computer-implemented method of claim 1, whereininitializing the storage device includes creating the table of contents,reserving a physical area of the storage device for the table ofcontents using a physical extent, and inserting the table of contentsinto the storage device, where the table of contents has the determinedsize of the table of contents, the determined location for the table ofcontents within the storage device, and the determined type of the tableof contents.
 6. The computer-implemented method of claim 1, furthercomprising determining that an amount of data used by the table ofcontents within the storage device has reached a predetermined size. 7.The computer-implemented method of claim 6, further comprising creatingan additional portion of the table of contents that is not contiguous tothe table of contents within the storage device, in response to thedetermination that the amount of data used by the table of contentswithin the storage device has reached the predetermined size.
 8. Thecomputer-implemented method of claim 7, further comprising linking theadditional portion of the table of contents to the table of contentswithin the storage device.
 9. The computer-implemented method of claim1, further comprising analyzing a number of data sets within the storagedevice and the size of the storage device.
 10. The computer-implementedmethod of claim 9, further comprising changing the type of the table ofcontents, based on the analyzing.
 11. A computer program product fordynamically managing a table of contents, the computer program productcomprising a computer readable storage medium having programinstructions embodied therewith, wherein the computer readable storagemedium is not a transitory signal per se, the program instructionsexecutable by a processor to cause the processor to perform a methodcomprising: receiving, by the processor, a request to initialize astorage device; identifying, by the processor, a size of the storagedevice to be initialized; determining, by the processor, a size of thetable of contents and a location for the table of contents within thestorage device, based on the identified size of the storage device to beinitialized; determining, by the processor, a type of the table ofcontents; and initializing, by the processor, the storage device,utilizing the determined size of the table of contents, the determinedlocation for the table of contents, and the determined type of the tableof contents.
 12. The computer program product of claim 11, wherein avolume serial number associated with the storage device is received withthe request to initialize the storage device.
 13. The computer programproduct of claim 11, wherein the table of contents stores a size ofstored data, a location of the stored data, permissions associated withthe stored data.
 14. The computer program product of claim 11, whereinthe type of the table of contents includes an operating system volumetable of contents (OSVTOC) type where free space within the table ofcontents is mapped by data set control block (DSCB) records within thetable of contents.
 15. The computer program product of claim 11, whereininitializing the storage device includes creating the table of contents,reserving a physical area of the storage device for the table ofcontents using a physical extent, and inserting the table of contentsinto the storage device, where the table of contents has the determinedsize of the table of contents, the determined location for the table ofcontents within the storage device, and the determined type of the tableof contents.
 16. The computer program product of claim 11, furthercomprising program instructions executable by the processor to cause theprocessor to analyze a number of data sets within the storage device andthe size of the storage device.
 17. The computer program product ofclaim 11, further comprising program instructions executable by theprocessor to cause the processor to determine that an amount of dataused by the table of contents within the storage device has reached apredetermined size.
 18. The computer program product of claim 17,further comprising further comprising program instructions executable bythe processor to cause the processor to create an additional portion ofthe table of contents that is not contiguous to the table of contentswithin the storage device, in response to the determination that theamount of data used by the table of contents within the storage devicehas reached the predetermined size.
 19. The computer program product ofclaim 18, further comprising further comprising program instructionsexecutable by the processor to cause the processor to link theadditional portion of the table of contents to the table of contentswithin the storage device.
 20. A system, comprising: a processor andlogic integrated with and/or executable by the processor, the logicbeing configured to: receive a request to initialize a storage device;identify a size of the storage device to be initialized; determine asize of a table of contents and a location for the table of contentswithin the storage device, based on the identified size of the storagedevice to be initialized; determine a type of the table of contents; andinitialize the storage device, utilizing the determined size of thetable of contents, the determined location for the table of contents,and the determined type of the table of contents.